Though the links in the chain of Dependent Origination are cyclical in
nature, Avijjā is the one that can be said to be the root of deception
and the primal cause of the infinite repetitions of the cycle. Also,
it is present in each and every link all the time.
Correct. Every link includes ignorance within it. For example, the consciousness link does not mean consciousness itself but, instead, a consciousness polluted with ignorance. SN 22.81 makes this clear, with its phrase: "contact with ignorance (avijjāsamphassajena)".
So, as an example, though Avijjā gives rise to Saṅkhāras, it is
Saṅkhāras (plus Avijjā),
Correct. Very good.
that gives rise to Viññāna and, in turn, it is Viññāna (plus Avijjā)
that leads us to the next Nidāna, i.e., NāmaRūpa, and, so on and so
forth.
Correct. Very good. A Buddha/Arahant has consciousness without ignorance (It 44; MN 38; MN 148; etc).
The ‘self’, the deceptive ‘individual’, is present only in an
incipient form till, I feel, up to the Nidāna of Phassa and starts
getting organized, as it were, from the link of Vedanā, getting
totally entrenched
In the most primal form of dependent origination, the above is incorrect. Refer to SN 12.12, which says there is no "self" or "who" that feels, craves and clings.
However, when past becoming emerges at ignorance, then 'yes', the deceptive self is in incipient form. (Refer to the end of MN 9, which includes three asava, including becoming, within the ignorance link)
and almost ‘irreversibly solidified’ by the time the level of Upādāna
is reached
Correct. In the most primal form, the self-view emerges at upadana. Refer to MN 9 or SN 12.2, which say words about self is one of the four types of attachment.
The weakest links are those of Vedanā, Taṇhā and Upādāna, and that is
why it is possible to break the chain at these three places, the
relatively easiest being the passage from Phassa to Vedanā and the
most difficult that from Taṇhā to Upādāna.
Correct. Most suttas are about preventing vedana causing craving to arise. MN 148 is one sutta that extends the possibility to craving; where craving can still be experienced without upadana. But once upadana arises, this is dukkha; this is stress or bondage.
Before Phassa, the ‘self’ is too vague and incipient and, therefore,
quite weak to attempt its own break-up.
As said, on the primal level, there can be no self prior to upadana.
However, if there is the incipient self arising at ignorance, it can be stopped at nama-rupa link. It does not have to proceed to contact.
For example, the incipient self thought (sankhara) may spontaneously arise during meditation: "I want to eat". Nama-rupa can reflect: "No, it is not the right time to eat". Therefore, the sense bases & contact that ordinarily look for food to eat will not arise. The chain is cut at nama-rupa.
Note: The namarupa link also includes contact within it. This refers to the 'internal' contact made with the sankhara link. It does not refer to the six-fold contact which is 'external' orientated contact.
After the Nidāna of Upādāna, the ‘self’ is too deeply entrenched and
solidified and, therefore, its break-up again becomes almost
impossible.
Yes. But the self that has formed can still be cut.
Is this right? Am I only partly right? Or, is it that I have got it
all wrong?
Your analysis is excellent. Well-done.
And yes, is it possible to have a profound insight directly into the
primal link of Avijjā, so that the later interventions are not
required at all?
MN 9 includes the three 'asava' within the link of ignorance, namely, sensuality, (past) becoming and ignorance. Therefore, if the mind has silent clear concentration, it can experience the energy or vibration of 'asava' bubbling up or flowing out, without those asava brewing up thoughts & perceptions (which are the vaci & citta sankhara). However, such outflows of 'asava' will always stir-up/agitate the breathing (kaya sankhara).
In summary, on the most primal level, the subtle emergence of ignorance can be discerned within the breathing. This is why Anapanasati is developed.
Note: The 'kayasankhara' mentioned at 4th step of anapanasati is the same as the kayasankhara mentioned in 2nd link of dependent origination.
It is important to know what the 'sankhara' are, which are of three types:
- kayasankhara - breathing
- vaci sankhara - initial & sustained thought
- citta sankhara - perception & feeling
When ignorance/asava brew up, they then brew up one or all of the above sankhara.
If required, refer to Thanissaro's excellent 'Shape of Suffering', pages 3 to 7.